Events Calendar

“Brillouin Scattering Slow Light in Fibers, and Secure Optical Key Generation”

SPEAKER: Dr. Avi Zadok, Post-doctoral Scholar, CalTechABSTRACT: Stimulated Brillouin Scattering (SBS) is a non-linear propagation effect which couples between a strong pump wave and a typically weak probe wave in an optical fiber. The gain process experienced by the probe wave is accompanied by a controllable group delay. In recent years, SBS has been widely used for the variable delay of high-rate data streams (slow and fast light), for a potential application of optical buffers [1]. In the first half of the talk, several less-known aspects of SBS-based slow light, which could lead to a broader range of applications, will be demonstrated. First, the maximum usable delay may be extended through careful optimization of the pump wave modulation, and control of its spectrum. Second, SBS can be applied to process and delay analog waveforms. Such processing is highly attractive, for example, in optical beam-forming in broadband, phased array antennas [2]. Finally, SBS is strongly dependent on polarization and fiber birefringence. This dependence may be used for locking and synthesis of the output probe state of polarization.
The second half of the talk will be dedicated to a novel protocol for secure key generation in the optical domain. The proposed scheme is based on establishing Ultra-long Fiber Laser (UFL) oscillations along a link between two users [3]. The key bits in the UFL system are represented by the choices of spectrally-selective mirrors made by the two users. While these choices can be simply determined by the legitimate end users, they may not be reconstructed by an eavesdropper employing either time or frequency domain attacks. Unlike quantum key distribution protocols, the UFL system consists entirely of standard, off-the-shelf fiber-optic components. The system allows for the use of amplifiers, and its bit rate decreases only linearly with distance. Experimental results demonstrating secure code generation will be presented.[1] Z. Zhu et al., J. Lightwave Technol. 25, 201-206, 2007
[2] A. Zadok et al., Photonics Technol. Lett. 19, 462-464, 2007
[3] J. Scheuer and A. Yariv, Phys. Rev. Lett. 97, 140502, 2006BIO: Avi Zadok received his B.Sc. in Physics and Mathematics at the Hebrew University, Jerusalem in 1994, and the M.Sc. and Ph.D. degrees in Electrical Engineering at Tel-Aviv University in 1999 and 2007. His Ph.D. research areas included dynamic optical filters, statistical optics, optical communications and slow light. He is presently a post-doctoral scholar with the group of prof. Amnon Yariv at Caltech, where his work concentrates on active Silicon photonics and optical communications. HOST: Prof. Alan Willner, willner@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 539

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher